Your largest customer costs more to serve than they pay you. What do you do about that architecturally?

Short answer

Earn the right to the claim by attributing infrastructure cost per tenant, then separate cost caused by their usage shape from cost caused by your own design. Architecture can change the shape; the decision about who pays is commercial, and it needs the engineering evidence to happen at all.

This is unit economics with architecture attached. Good unit economics asks what it costs to serve one customer, one tenant, one workflow, or one heavy account, then separates unavoidable cost from design choices. Cost attribution matters because without cost attribution the customer looks profitable in revenue and invisible in infrastructure. Strong unit economics work uses cost attribution to decide whether to reprice, redesign, rate-limit, isolate, or walk away.

Unit economics is the language that turns an expensive customer from an anecdote into a pricing, architecture, or support decision.

Unit economics should be measured before the renewal conversation, not after the margin surprise has already become political.